The present disclosure relates generally to adjustable vehicle seat assemblies utilizing power track systems. More particularly, the present disclosure relates to enhancements to a power track system and its transmission.
Vehicle seat assemblies are typically provided with a track system that enables the forward and rearward positioning of the seat assembly. Such adjustment capability is desirable to enable vehicle operators of various sizes to be seated comfortably within the motor vehicle. Such seat assemblies typically include a track assembly including two tracks that move relative to one another and a latching mechanism that retains the tracks (and therefore the seat assembly) in a locked position relative to one another until the latch mechanism is released. The tracks may be moved relative to one another, which allows the occupant of the seat assembly to adjust the seat assembly to a new position.
Some vehicle seat assemblies include an electric motor, a transmission and a lead screw positioned within the track assembly for power adjustment of the vehicle seat. In such arrangements, the lead screw may generally be fixed and does not rotate. The transmission includes a worm gear assembly rotatably coupled to the lead screw and the electric motor causes the worm gear to rotate causing the transmission to translate along the fixed non-rotating lead screw to adjust the vehicle seat assembly forward or rearward.
In such configuration, the electric motor, mounted on a traverse beam is positioned relative to each of the tracks, for example in the center of the tracks or at one end of the tracks. A transmission mounting bracket couples the transmission, which may float inside of the mounting bracket, and the stationary lead screw to one of the rails. Thus, the strength of the power track is realized through the transmission mounting bracket. In the event of a collision, the load on the bracket could cause the bracket to bend. Using a larger bracket to provide more strength to the power track could be problematic due to space constraints inside the track section that limits the size of the mounting bracket.
Occasionally, the movement of the seat forward can place the occupant of the vehicle too close to airbags that are located in front of the occupant. In such arrangement, the power to the air bag could be diminished or turned off. Generally, it is known to provide a seat position sensor for controlling the airbag based upon seat position. However, such known seat position sensors are affected by debris (such as dirt and dust) in the passenger cabin of the vehicle.
Therefore there is a need for a stronger transmission mounting bracket that can withstand the extra load encountered in situations such as a vehicle collision. There is also a need for a compact design of a sensor arrangement that can detect the position of the seat in reference to the proximity of an airbag and adjust the airbag power down or off as needed.